


Time Reveals All

by augmentedfourth



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Desk Sex, F/M, Plot What Plot/Porn Without Plot, Porn with Feelings, Romance, Vaginal Sex, silver snow
Language: English
Status: Completed
Published: 2020-06-12
Updated: 2020-06-12
Packaged: 2021-03-03 21:34:39
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,112
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24672421
Author URL: https://archiveofourown.org/users/augmentedfourth/pseuds/augmentedfourth
Summary: Seteth is in love with Byleth—as much as he may try to deny it—yet is afraid to reveal too much to her, from what he's learned about her past to his true feelings. She finds him in his office late one night and insists on having the awkward conversations he's been trying to avoid. Despite his concerns and his tendency to overthink everything, he just may be surprised by what she has to say.
Relationships: My Unit | Byleth & Seteth, My Unit | Byleth/Seteth
Comments: 4
Kudos: 62





	Time Reveals All

Endless stars dotted the inky night sky, the tiny pinpricks of light twinkling high above the monastery. Seteth stood at his office window, hands clasped behind his back, staring out through the patterned panes at the celestial display. There was so much to do, so many plans to formulate, all while the threat of hidden dangers lurked around every corner. He needed to focus on his lengthy list of tasks, and any distraction or exploited weakness could lead to disaster. Still, no matter how hard he tried to avoid it, something always tugged at the back of his mind, a constant presence impossible to escape.

The professor.

Byleth.

_Her_.

He’d been suspicious of her when she’d first arrived at Garreg Mach, but he’d had no choice but to trust Rhea and stand by her decisions. He’d grown more intrigued by her as he uncovered snippets of her past. Over time, he found he actually enjoyed her company, limited as their interactions were, and quietly admitted to himself she was a valuable asset to the monastery.  
Then their whole world as they knew it changed.

For five long years, war ravaged the land, and survival was prioritized above everything else. Every now and then, he’d allowed his thoughts to drift to her, and lamented what he assumed was her tragic demise. When she reappeared before him, though, as flawless as ever and ready to fight by his side, he could no longer deny what had been building inside him.

He loved her.

Seteth shifted his weight as he continued to gaze out the window. From the moment he saw her again, he vowed to protect her at all costs. The future of Fódlan depended on them, he was sure of it. He tried to convince himself it was a purely pragmatic plan and had little to do with his personal feelings. Yet on moonless nights such as this one, he allowed himself to indulge in his hidden emotions and deepest desires.

It was difficult to pinpoint what, precisely, had drawn him to her. Over the course of his prolonged lifetime, plenty of women had crossed his path, yet few had sparked his interest. When she first came to the monastery, she spoke little and rarely displayed any emotion. As time passed, however, he watched her open up and grow with her students, sharing in their tears and laughter, their failures and triumphs. On a few occasions, he’d caught a glimpse of a genuine smile from her, and it was enough to stoke the embers in his heart he’d considered extinguished long ago. During his research into her history, he’d heard similar hushed whispers about her mother, rumors of how her smile could light up a room and—

The sound of footsteps at his office door opening jerked his thoughts back to the present. When he turned around, his breath caught in his throat, yet he remained standing stiffly by the window. “Professor,” he greeted his visitor. “You’re up late tonight.”

“As are you.” Byleth gestured to the nearest sconce on the wall. “I noticed the light from the hallway and wanted to make sure the flames hadn’t been left unattended.”

“Thank you.” Logically, he knew there was no way she could have heard his private thoughts, but a flush of embarrassment crept up his neck. “Is there anything else you need?”

She closed the set of doors behind her and leaned against them, remaining in the small recess at the entrance to his office. Shadows darkened her face and she didn’t respond right away. After what felt like hours, she lifted her chin and spoke. “There’s a lot you hide from me,” she said plainly.

It wasn’t an accusation, more of a simple statement in her usual blunt manner he’d grown to find charming. Regardless, it wasn’t an answer Seteth had been expecting, and a twinge of guilt knotted in is stomach. “I know. And I’m sorry.” He rubbed at his temples with his thumb and forefinger. “I promise I will one day tell you everything I know and hope you find it satisfactory. But the risks are too great right now. I can’t let anything distract us or shatter our focus until those we’ve sworn to protect are safe.”

He half-expected an argument, but none came. She nodded, her back still pressed to the doors. “While you omit a lot of details, at least you’re honest with what you do say to me. I appreciate that.”

The compliment felt hollow, yet he had no choice but to accept it. “I am trying, I assure you,” he said. “Anything else?”

Byleth crinkled her nose, seeming to give every word careful deliberation before she spoke it aloud. “I’ve noticed the way you look at me when you think no one else is watching.”

The air whisked from his lungs. He pressed his lips together, fighting to maintain his composure. He realized that as with her previous statement, there was no accusatory tone, but shame still gnawed at him. Attempting to deny it would go against what he’d just vowed to her and would make him feel even worse. “I apologize,” he said. “It was not my intention to make you uncomfortable.”

Her pale green eyes glittered in the darkness. “You didn’t.”

“Either way, it was wrong of me.” Seteth glanced to the side, averting his gaze. “I thought I was being discreet, but clearly, I was mistaken. I do apologize, and it will not happen again.”

Byleth stepped out of the shadows, her cloak swishing behind her as she moved forward. “You’re always so determined to keep track of everything around here. But in all your attention to everyone’s activities, their various comings and goings….” She took another step toward him. “You never saw me looking back.”

His mouth grew dry. “...Ah.”

Another few steps and she was directly beside him, peering up at him through her long, dark lashes. “Is something wrong?” Her lips curved downward. “I thought you’d be happy if I told you how I felt.”

“Goodness, no. Nothing’s wrong.” He’d been caught off guard, and it seemed like everything was happening faster than he could keep up with. “I’m flattered, believe me. But also a bit surprised, as I’d never dreamed—”

“You’re important to me.” She tilted her head to the side. “I enjoy the time we spend together, and I’d like to do so more often.”

Seteth debated whether to share his doubts with her, the idea of revealing his vulnerabilities adding to his discomfort. His new goal of always being honest with her won out in the end, though. “I have to ask,” he said, his voice sounding less steady than he would have hoped. “Why me? You’ve got an army of young, attractive men and women who would follow you to the ends of the world, and I’m sure more than one of them has had some scandalous thoughts about their former teacher. You could have your pick of any of them if you so desired.”

“That doesn’t matter. They’re not you.” Byleth laid her hands on his arms where they were still folded in front of his chest. “And I didn’t want to wait any longer to tell you. I _couldn’t_.”

Her touch radiated heat even through the thick fabric of his coat. The way she stared up at him, so joyous and eager, was better than anything he’d ever conjured up in his private fantasies. Uncrossing his arms, he reached out for her, his hand hesitating for a brief moment before he cupped her cheek and let the tips of his fingers tangle in her hair.

Seteth closed his eyes and ducked his head down to press his lips against hers. They were soft and inviting, the kiss emanating a long-forgotten warmth he hadn’t realized he’d missed. When she opened her mouth to allow his tongue inside, he thought his knees might buckle from the overwhelming rush of emotion. _How long_ had _it been_? he thought as he kissed her.

She slid her hands up to his shoulders and pulled him closer. As much as he yearned to satisfy his awakened cravings, something held him back, and he pulled away. “We shouldn’t be doing this,” he mumbled.

Byleth’s stare never wavered. “Why not?”

“Because so much else demands our time right now. We must protect the monastery and its residents, all while plotting our next strategy. So many people are relying upon us to guide them, and we cannot falter.” He tried to force a smile for her behalf. “I want to be able to give you my undivided attention and everything you deserve, and I’m afraid now is not the right time for that.”

She shook her head. “You and I have both lost people close to us. It’s too easy to keep putting things off for a later date, and then have it all wrenched away out of nowhere.” Taking one of his hands in both of hers, she raised it, her grip strong. “I don’t want that to happen to us,” she whispered, pressing his palm against her chest.

The slivers of pale skin exposed by the top of her shirt were smooth and warm beneath his touch. With every breath, the swell of her breasts rose to meet him, and he choked back a groan. He was an old man, a patient man, and he’d always been able to rise above what he considered such base desires, but something about her threatened to destroy any semblance of restraint he had left.

While Seteth battled with his innermost thoughts, she inched closer, never loosening her grasp on him. “We _need_ this.”

All his reasons for resisting melted away when their lips met again. Byleth released his hand in order to wrap her arms around his neck, flattening her body against him. Driven forward by hunger, he delved farther into her mouth, exploring her with his tongue and delighting in every playful swirl he received in return. He planted one hand on the small of her back to keep her close and let the fingers of the other, still trapped between them, sink into the pliant flesh of her chest.

A faint giggle reverberated against his lips as she writhed in his embrace. She stepped backward without letting go of him, guiding him along with her. He followed her lead, his hips colliding with hers when they reached the edge of his desk. At the impact, his rigid cock pressed into her, throbbing with heat. There was no way she couldn’t feel its outline even through his heavy clothes, but he no longer cared.

Without breaking the kiss, she tugged at the high collar of his coat. He released her waist with the intention of helping her out, but her nimble fingers made quick work of the large number of buttons, buckles, and other closures. Before he knew it, she’d pushed the garment off his shoulders, letting it drop to the floor and revealing the thin cotton shirt he wore underneath. The cool air settling over his skin did little to quell the fires burning inside him.

Byleth pulled away, wriggling out from where she’d been pinned against the desk. She unfastened her cloak and added it to the growing pile on the carpet. Hopping up on the end of the desk, she kicked off her boots and leaned back on one hand. Her hair had fallen across her eyes, but there was no diminishing their eager sparkle. From the pink flush in her cheeks to her parted lips, still moist and swollen from their passionate kiss, sensuality radiated from every inch of her. Seteth found the effects surprising…and irresistible.

He stood between her knees, his body already aching from the loss of contact. Her fingertips danced down his chest to the hem of his shirt; that, too, was removed with haste and flung to the floor. “I was going to ask you one last time if you’re sure about this,” he said. “But you certainly seem to have your mind made up.”

She traced the ridges of his torso with a feathery touch, from the outline of his pecs down across the firm plane of his stomach. Her bright eyes followed her movements, and were it not for the small smile upon her face, he would have felt self-conscious about her intense exploration of him. “I didn’t think I’d find you in here when I wandered by tonight,” she said. “And then I didn’t expect our conversation to lead where it did.”

As she spoke, her hands never stopped roaming over his skin, leaving fiery trails wherever they traveled. “I like the idea of us being more honest and open with each other,” she continued. When she reached the waistband of his pants, she used it to yank him forward, her gaze finally rising to meet his. “So, now that I know you feel the same way, I don’t want to wait one moment longer.”

Her thighs tensed around him, erasing any lingering doubts. His heavy cock strained against the confines of his pants, but there were still several barriers in his way. Seteth recaptured her mouth in another scorching kiss and slipped one hand behind her back. Sliding his hand up her spine, he located the zipper of her cropped top. He dragged it down with painstaking deliberation, anticipation simmering in his veins.

Byleth allowed him to ease the shirt off her arms before leaning back on the desk, her bare chest jutting up in the space between them. He caressed the side of one full breast, stifling a groan as his fingers fondled the soft flesh. She looked and felt better than he ever could have imagined, and despite her pleas to move quickly, he wanted to commit every detail to memory.

A high-pitched gasp left her mouth when he swiped his thumb across her nipple. He silenced it with a kiss, then skimmed his lips down her throat and over her collarbone. Leaning over her, he let his mouth take over his hand’s explorations, savoring the way her quivering breasts felt as he kneaded and nuzzled them.

Her hand fisted in the hair at the back of his neck and her spine arched. “One day,” he murmured between sharp nibbles and soothing kisses, “one day, when we can finally take some time for ourselves, I intend to bring you into my chambers and stay there from dawn until dusk.” He caught one nipple between his teeth and gave it a tug. “I want to take my time getting to know every inch of you.”

She gasped when he sucked down hard, increasing his pressure while he swirled his tongue around the stiff peak. “I look forward to it. And I look forward to creating a world where we can make that happen.”

Byleth reclined all the way, causing him to nearly collapse on top of her. He continued peppering kisses over her heaving chest before making his way back to her mouth, unsure which part of her he wanted to devour next. While he deliberated, she snaked her hand between them and let her fingers skate over the length of his engorged cock. Murmuring a noise of what he hoped was appreciation against his lips, she gave his shaft a firm squeeze through his pants.

A low growl rumbled in his throat. Breaking away, he buried his face in her shoulder, his forehead resting against the solid wood of his desk. All the pent-up energy from sleepless nights threatened to explode out of him as she rubbed his cock with long, slow strokes, but he managed to maintain control of himself. _Barely_ , he thought as he straightened, marveling at how her presence beneath him was more sensual, more intoxicating than he ever would have imagined.

Standing over her, Seteth trailed his fingers over her stomach, arriving at the top of her shorts. She lifted her hips, and he slid them down and off. Her patterned tights followed, and despite the heady rush coursing through his veins, he took care not to tear the flimsy material, kneeling as he slipped them over the curve of her legs.

When he rose again, the sight that greeted him was magnificent. In his imagined fantasies, he had envisioned a proper courtship—long walks, formal meals, possibly accompanied by some hand holding and even a stolen kiss or two. Yet now, as he gazed upon her exposed form splayed out atop his desk, her messy hair framing her delicate features and her heavy breasts bobbing with each breath she took, he was enthralled. The scene was raw, unexpected, and free of inhibition. It was _her_.

And it was perfect.

He wasted no time in shedding the remainder of his clothing. Her thighs parted, and he positioned himself between them. Never escaping the intensity of her sea-green gaze, he ran one finger down the length of her slit and was pleased by both the wetness he found and the tremble he elicited. He guided his cock, thick and swollen in his hand, to the entrance of her sex and pushed forward, penetrating the soft folds.

A whirlwind of sensations flooded Seteth’s nerves as he sank inside her, from flashes of past memories to snippets of his more current daydreams. Her tight inner walls enveloped him, a flawless fit. Breathless, he stood still for an infinite moment, overwhelmed by the haze clouding his mind.

Byleth’s hands on his biceps brought him back to reality. Her fingertips dug into his corded muscles as he thrust into her, gliding in and out of her in a steady tempo. She bucked up to meet him, every collision of their bodies punctuated by a gasp or moan. The melodious sounds propelled him onward, compelling him to bring her the utmost pleasure.

Sweat beaded on his forehead. Somehow, he needed more. He slowed his momentum and, without withdrawing from her, slid his hands down her legs and grabbed her ankles. One at a time, he hooked each leg over his shoulders, pausing to place a gentle kiss on one shapely calf before slamming into her as hard as he could.

She squealed in surprise, a wide grin blossoming on her face. For a split second, he worried about someone outside hearing them, but his lust for her won out over anything else. Leaning into her with his full weight, he plunged into her again and again, as deep as he could go. She clung to his arms, her knees by her ears, and panted for air.

The first twinges of release coiled inside him. With a primal groan, he speared her with his cock, the force so great he thought the desk underneath them might collapse. Byleth clenched around him, writhing beneath his onslaught but pinned in place. Her spasms coaxed forth every last drop of his seed, drawing him even farther into their intimate contact.

The warmth of her embrace guided him down from his euphoria. He planned to remain by her side for as long as she wanted, but the desk, sturdy though it was, offered them little comfort. Dreams of bringing her to his bed still danced through his thoughts, but he didn’t want to risk slinking through the hallways in their current state.

Thinking quickly, Seteth bent over and grabbed his long coat from where it had fallen. Before she could say anything, he scooped her into his arms and carried her across the room to the plush armchair in the corner. He sat down, letting her curl up in his lap, and arranged the coat over their entwined bodies as best he could to ward off any chill in the air. Yet again, it was not the plan he would have executed had he been given more advance notice, but the way her body fit so perfectly alongside his erased his misgivings.

He tilted his head back and closed his eyes, his mind racing as he replayed everything that had just happened and considered its implications for the future. Above all, simply being with her like this was nothing short of exhilarating. He toyed with the ends of her hair, letting its softness tangle in his fingers as she nestled her head in the crook of his neck, her breath warm near the base of his throat. One of her hands rested on his collarbone, claiming what was now hers.

The weight of her supple breasts pressed against his chest. Every time she shifted, the heat of her bare skin ignited a new series of sparks inside him. He held her close, content to sit with her until dawn, but there was no denying the erection stirring between his legs.

Byleth trailed her hand down the front of his torso, her fingertips grazing his steely shaft. “You never do rest, do you?” she murmured into his shoulder.

“I, ah….” He inhaled, glad he could avoid her piercing gaze for once. “I must confess, it has been a long time since I have been with a woman, never mind someone as captivating as yourself. A very long time.”

Her body tensed, his cock cradled in her palm. After what seemed like hours, she finally spoke again. “How long?”

Seteth didn’t answer.

While he struggled to find a response that was truthful yet didn’t reveal too much, Byleth twisted in his grasp. With one leg on either side of his lap, she ground against him, rubbing her dampened slit along his rigid erection. As her hips rolled forward in a sensuous rhythm, she cupped the sides of his face. Her glimmering green eyes locked onto his as she caressed his jaw. “How long?” she repeated.

He groaned as she teased at him, conflict yanking him in two different directions. However, as he lost himself to her ardent stare, he knew he couldn’t lie to her. “ _Centuries_ ,” he breathed.

She leaned forward, brushing her lips across his. Her hips lifted just enough for him to maneuver his cock between her legs. She sank down, letting him fill her for a second time, and placed her palms on his chest.

Slowly, deliberately, she rocked against him. He throbbed inside her, willing to let her set the pace, yet yearning for more. His hands traversed her body, skimming over every inch of flushed skin he could find. Finally, he settled for draping his hands around her waist, fondling her fleshy curves.

Little by little, she increased her speed, all while transfixing him with her intense stare. Those fathomless eyes could see straight into his soul, Seteth thought, and he knew his days of hiding anything from her were over. Any questions she had, any knowledge she sought, it was all hers. If she believed they were meant to be together, he’d give all of himself to her, and he swore to never let her down.

As she gyrated in his lap, he stroked the crease of her thigh. Her breath hitched in her throat, and he let his fingers drift closer to the junction of their bodies. When his thumb found the sensitive bundle of nerves at the apex of her sex, she jolted, and an impassioned moan escaped her throat.

He applied more pressure, rubbing in concise circles. Byleth’s head tilted back, her lips parted as her expression revealed the pleasure he incited. He drank in the spectacular sight, refusing to relent in his precise movements. Her legs tightened around him, then slackened as tremors overtook her limbs, her orgasm cascading through her. It was enough to tip him over the precipice, and he joined her, thrusting upward as if his body was no longer his to control.

Byleth collapsed on his chest, her arms wrapping around him as her breathing slowed. He returned the embrace, holding her tight. So much of the night had seemed like a dream, yet the scent of her hair and the weight of her body sprawled across his reminded him that what they’d shared with each other was real.

Despite acknowledging his good fortune and taking a moment to indulge in his gratification, Seteth knew the sunrise was mere hours away, and the new day would bring about a fresh set of risks and challenges. Keeping her folded in his grasp, he brought his lips to her ear. “I meant what I said earlier,” he whispered. “The day will come when we can be together without anything or anyone standing in our way.”

“I believe you. But I’m not worried.” She arched her back, stretching in place, but not yet getting up from the chair. “We have all the time in the world.”

**Author's Note:**

> Thoughts in no particular order:
> 
> 1) So far I've only finished the Silver Snow path, but I tried to keep a lot of this vague so it might fit in elsewhere as well.
> 
> 2) Seteth seems like the type to discuss everything to death before finally doing something, but oh well, I love him anyway. Good thing it still worked out for him here.
> 
> 3) Slightly awkward yet still endearing Byleth makes the most sense to me. You know, with *gestures vaguely* everything surrounding her past and stuff.
> 
> 4) Damn, writing about their outfits and how they must get dressed/undressed was a challenge.


End file.
